Glycine is an inhibitory amino acid neurotransmitter that only acts on receptors which bring out an enhanced chloride conductance. It shows highest concentrations in the spinal cord as compared to elsewhere in the brain. However, it interacts with and allostericaly activates the excitatory receptor N-methyl-D-aspartate (NMDA), thus, resulting in excitatory transmission in brain. Glycine is an inhibitory amino acid neurotransmitter that only acts on receptors which bring out an enhanced chloride conductance. It shows highest concentrations in the spinal cord as compared to elsewhere in the brain. However, it interacts with and allostericaly activates the excitatory receptor N-methyl-D-aspartate (NMDA), thus, resulting in excitatory transmission in brain.